79 300sd 617.950 how similar to 83 617.952
 

Can I use a donor 1979 300SD Turbo motor in a 1983 300SD ?
The 79 lists 617.950 and the 83 says 617.952.

I can visually see that the vacuum pump is very different (even different from my 1980 and the 81).
Guessing I can switch in the newer vacuum pump.

Turbo looks the same, same location of alternator, AC compressor, Power steering pump.

So, does anyone think this engine is a good donor for any 1981 to 1984 Turbo engine ?

Thanks for all your help.

IMO, that swap is doable, but I don't think the vacuum pumps interchange. There will be some issues with vacuum (no EGR on the .950). Going the other way ( .952 into a W116 chassis) does not work unless you change the upper oil pans. The .950 had less horsepower until 1980, though, and there may be issues with non-hardened cams.

The interesting thing is that although it lists 10 less hp, my 79 SD is faster throughout the whole range then my 85 300D.

Your 79 has a lower final gear ratio than your 85.